Hello,
After reading so much about this little driver did pull the trigger on 8 of them.
Goal is to build a WMMTMMW or WMMMMW + T beside configuration.
Bass would be SB20 with active filtering, drivers aligned for 90DB. No external sub.
Crossover W-M would be 160 to 200Hz
And crossover M-T could be:
around 2000Hz if MMTMM
around 4000Hz if MMMM and T beside, due to closer mid drivers (wanting to avoid comb filtering)
Side tweeter looks more appealing because 4000Hz gives more choice, and leaves a wide range to the TC9 for a more coherent sound
What would be the impact on imaging of not having the tweeter on same axis as other drivers ?
My experience so far is WAW (crossed between 80 and 160 depending on projects), mostly with Jordans.
Tweeter not selected yet, will depend on configuration.
Thanks for advise!
François
BTW did already simulate and all excursions are fine even at higher SPL than needed (measuring 85DB at 3 meters when watching rock concerts)
After reading so much about this little driver did pull the trigger on 8 of them.
Goal is to build a WMMTMMW or WMMMMW + T beside configuration.
Bass would be SB20 with active filtering, drivers aligned for 90DB. No external sub.
Crossover W-M would be 160 to 200Hz
And crossover M-T could be:
around 2000Hz if MMTMM
around 4000Hz if MMMM and T beside, due to closer mid drivers (wanting to avoid comb filtering)
Side tweeter looks more appealing because 4000Hz gives more choice, and leaves a wide range to the TC9 for a more coherent sound
What would be the impact on imaging of not having the tweeter on same axis as other drivers ?
My experience so far is WAW (crossed between 80 and 160 depending on projects), mostly with Jordans.
Tweeter not selected yet, will depend on configuration.
Thanks for advise!
François
BTW did already simulate and all excursions are fine even at higher SPL than needed (measuring 85DB at 3 meters when watching rock concerts)
I suppose you can achieve great results with both approaches.
There are many posibilities, idealy you should make mock up build on cardboard and measure.
Some like symetry mmtmm, some square mids with tweeter in the middle, some on the side of mmmm.
There are those who prefer mmmt, or similar.
Way too many options. That's why its not possible to say which one is best.
There are many posibilities, idealy you should make mock up build on cardboard and measure.
Some like symetry mmtmm, some square mids with tweeter in the middle, some on the side of mmmm.
There are those who prefer mmmt, or similar.
Way too many options. That's why its not possible to say which one is best.
Thx, nice inspiration!
Will order a pair of small Dayton tweeters (35mm only for a MM spacing of 9.8mm in square or 11.8mm in MMTMM and will play with some extruded polystyrene boards. Quite curious about the square mids approach as (due the 45° corners) that's the configuration with less spacing (except side tweeter). Should allow to cross near 3500Hz, is it high enough for such a small/cheap tweeter like the NB20-FB4? Listening at 85db/3m so should need to drive the tweeters with a couple of watts.
The last ones are beautiful.
Will order a pair of small Dayton tweeters (35mm only for a MM spacing of 9.8mm in square or 11.8mm in MMTMM and will play with some extruded polystyrene boards. Quite curious about the square mids approach as (due the 45° corners) that's the configuration with less spacing (except side tweeter). Should allow to cross near 3500Hz, is it high enough for such a small/cheap tweeter like the NB20-FB4? Listening at 85db/3m so should need to drive the tweeters with a couple of watts.
The last ones are beautiful.
Did a mockup with styrofoam this WE:
11 cm internal depth, 30cm wide
Equalized with Audissey => automatically crossed with 12" sub at 120hz. This was the first surprise, I did expect much higher (the 4 in line did cross at 180Hz)
Even with the missing tweeter and stereo subs, my Jordan VTLs are far behind in terms of dynamics and immersive sound. Thanks Adason for the inspiration.
Tried first 4 in a row and then the square pattern. Bass is totally different in this configuration.
Next step will be measurements (was lazy and let Audissey work for me today).
Dynamics is just crazy, it's a different league. I guess that comes from the 4 drivers series/parallel that work far from max.
That's enough for me to go on with the project and start building the final enclosure (also hosting a Dayton ND20FB-4 and a Dayton DCS-205).
As I want to play with MT crossover I'll go active (3-amping).
- 4 TC9 in a square pattern
- "Half" OB, wall mounted but with no sides (just top/bottom/back). Constraint here is wall-mounted and reasonably small.
- 7.5mm spacing between drivers (so to have space for a small Dayton tweeter in the middle. C2C = WL of 3500Hz
- Some stuffing for the back
11 cm internal depth, 30cm wide
Equalized with Audissey => automatically crossed with 12" sub at 120hz. This was the first surprise, I did expect much higher (the 4 in line did cross at 180Hz)
Even with the missing tweeter and stereo subs, my Jordan VTLs are far behind in terms of dynamics and immersive sound. Thanks Adason for the inspiration.
Tried first 4 in a row and then the square pattern. Bass is totally different in this configuration.
Next step will be measurements (was lazy and let Audissey work for me today).
Dynamics is just crazy, it's a different league. I guess that comes from the 4 drivers series/parallel that work far from max.
That's enough for me to go on with the project and start building the final enclosure (also hosting a Dayton ND20FB-4 and a Dayton DCS-205).
As I want to play with MT crossover I'll go active (3-amping).
For open baffle you need space behing, like 2-3 ft, that's more than half a meter.
Are you sure little dayton dome will be able to keep up?
Are you sure little dayton dome will be able to keep up?
Did listening off-axis, and eq done also off-axis. Sure I don't get the full benefits of OB, but here wall mounting is mandatory 🙂 . Measures will explain what's happening, need to find back the cable.
Will see with the Dayton...it is 90db, TC9s are 90,4, simulations give just a few watts for my listening level.
Wanted a small tweeter to limit TC-9 spacing... any clue of a more powerful one with such a small footprint, even with some rework?
Will see with the Dayton...it is 90db, TC9s are 90,4, simulations give just a few watts for my listening level.
Wanted a small tweeter to limit TC-9 spacing... any clue of a more powerful one with such a small footprint, even with some rework?
Quick and dirty measurements show an off axis30° curve that looses 2db (compared to on-axis) between 1k and 2k, then is stable from 2k to 4k then goes down by 8db from 4k to 8k, really starting to fall at 5k.
At 45° there is not much difference.
So crossover in the 3500-4000 should be OK (possible due to very close spacing thanks to small footprint of FD20), worth trying. Hoping that will limit power enough to let the tweeter survive.
Also have some bumps at 200 and 300hz (+-3db) maybe linked to the non real OB setup (sides open + stuffing), but they seem quite consistent / axis and should be manageable with DSP (will see 🙂 ). Doesn't match any of the dimensions of the box.
Measurements below 200hz aren't so relevant as I limited the sample to 100Hz-20000Hz. However, below 200Hz everything goes away at 17db/oct, starting to seriously fall below 175Hz, so subs will have to go that high, hoping that's manageable by DCS205.
This was also the opportunity to see the job done by Audissey : very very basic... seems it only plays with low Q filters, a real DSP manually tuned does much better. Did measure w/o audissey (with audissey ON it changes th general shape of the curve for off-axis listening but doesn't touch any of the bumps)
Now that's th emimiut of my competences with REW, and I'd like to better understand how to use the impulse / delay graphs to see if that translates the feeling of way higher dynamics than my Jordans.
At 45° there is not much difference.
So crossover in the 3500-4000 should be OK (possible due to very close spacing thanks to small footprint of FD20), worth trying. Hoping that will limit power enough to let the tweeter survive.
Also have some bumps at 200 and 300hz (+-3db) maybe linked to the non real OB setup (sides open + stuffing), but they seem quite consistent / axis and should be manageable with DSP (will see 🙂 ). Doesn't match any of the dimensions of the box.
Measurements below 200hz aren't so relevant as I limited the sample to 100Hz-20000Hz. However, below 200Hz everything goes away at 17db/oct, starting to seriously fall below 175Hz, so subs will have to go that high, hoping that's manageable by DCS205.
This was also the opportunity to see the job done by Audissey : very very basic... seems it only plays with low Q filters, a real DSP manually tuned does much better. Did measure w/o audissey (with audissey ON it changes th general shape of the curve for off-axis listening but doesn't touch any of the bumps)
Now that's th emimiut of my competences with REW, and I'd like to better understand how to use the impulse / delay graphs to see if that translates the feeling of way higher dynamics than my Jordans.